The formatR package is 11 years old now. Interestingly, my very first English blog post was about this package. The original implementation was 8 lines of code in total, which still works today.
In the 11 years, the code size has grown to 784 lines, which is roughly 100 times bigger, and this package still has zero R package dependencies. It has some soft dependencies, but they do not affect the core functionality.
$ wc -l R/*.R 33 R/eval.R 10 R/shiny.R …